The goal of this project is to adapt an existent single-access hemodialysis machine, the BioLogic-HD(tm), to perform night- time periotoneal dialysis with high dialysate volumes. A disposable package on this machine will include a 30 liter bag which includes dry premeasured amounts of NaCl, NaHCO3, glucose, and carboxylic amino acids. Under control of the BioLogic machine, 30 liters of pure and sterile water will be added to this bag. To create the pure and sterile water, a single- patient water purification system, the HD-100, will be supplied in modified form by Water Pure, Inc. Water will pass through granular activated charcoal, a 0.5 micron filter, a Filmtec(R) reverse osmosis membrane and a Minntech polysulfone hollow fiber ultrafilter. During Phase I we will first modify the BioLogic-HD and HD-100 and create the disposable package including the 30 liter bag. Then, we will integrate these into a single system with connections to transfer fluid through sterile connections, and monitor the volume of fluid through measurement with a scale in the BioLogic. Thorough in vitro tests will determine the sterility, chemical content, and tempature of the dialysate, and the safety, reliability, and sensitivity of the dialysis delivery system. If these tests are affirmative, then during Phase II of this project, we will focus on steps necessary to bring to market a night-time peritoneal dialysis machine capable of providing dialysis treatments which are more effective and less time-intensive than CAPD.